//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//  Plats (i.e. elevator platforms) code, raising/lowering.
//

#include <stdio.h>

#include "i_system.h"
#include "z_zone.h"
#include "m_random.h"

#include "doomdef.h"
#include "p_local.h"

#include "s_sound.h"

// State.
#include "doomstat.h"
#include "r_state.h"

// Data.
#include "sounds.h"


plat_t*     activeplats[MAXPLATS];



//
// Move a plat up and down
//
void T_PlatRaise(plat_t* plat)
{
    result_e    res;

    switch(plat->status)
    {
      case up:
    res = T_MovePlane(plat->sector,
              plat->speed,
              plat->high,
              plat->crush,0,1);

    if (plat->type == raiseAndChange
        || plat->type == raiseToNearestAndChange)
    {
        if (!(leveltime&7))
        S_StartSound(&plat->sector->soundorg, sfx_stnmov);
    }


    if (res == crushed && (!plat->crush))
    {
        plat->count = plat->wait;
        plat->status = down;
        S_StartSound(&plat->sector->soundorg, sfx_pstart);
    }
    else
    {
        if (res == pastdest)
        {
        plat->count = plat->wait;
        plat->status = waiting;
        S_StartSound(&plat->sector->soundorg, sfx_pstop);

        switch(plat->type)
        {
          case blazeDWUS:
          case downWaitUpStay:
            P_RemoveActivePlat(plat);
            break;

          case raiseAndChange:
          case raiseToNearestAndChange:
            P_RemoveActivePlat(plat);
            break;

          default:
            break;
        }
        }
    }
    break;

      case  down:
    res = T_MovePlane(plat->sector,plat->speed,plat->low,false,0,-1);

    if (res == pastdest)
    {
        plat->count = plat->wait;
        plat->status = waiting;
        S_StartSound(&plat->sector->soundorg,sfx_pstop);
    }
    break;

      case  waiting:
    if (!--plat->count)
    {
        if (plat->sector->floorheight == plat->low)
        plat->status = up;
        else
        plat->status = down;
        S_StartSound(&plat->sector->soundorg,sfx_pstart);
    }
      case  in_stasis:
    break;
    }
}


//
// Do Platforms
//  "amount" is only used for SOME platforms.
//
int
EV_DoPlat
( line_t*   line,
  plattype_e    type,
  int       amount )
{
    plat_t* plat;
    int     secnum;
    int     rtn;
    sector_t*   sec;

    secnum = -1;
    rtn = 0;


    //  Activate all <type> plats that are in_stasis
    switch(type)
    {
      case perpetualRaise:
    P_ActivateInStasis(line->tag);
    break;

      default:
    break;
    }

    while ((secnum = P_FindSectorFromLineTag(line,secnum)) >= 0)
    {
    sec = &sectors[secnum];

    if (sec->specialdata)
        continue;

    // Find lowest & highest floors around sector
    rtn = 1;
    plat = Z_Malloc( sizeof(*plat), PU_LEVSPEC, 0);
    P_AddThinker(&plat->thinker);

    plat->type = type;
    plat->sector = sec;
    plat->sector->specialdata = plat;
    plat->thinker.function.acp1 = (actionf_p1) T_PlatRaise;
    plat->crush = false;
    plat->tag = line->tag;

    switch(type)
    {
      case raiseToNearestAndChange:
        plat->speed = PLATSPEED/2;
        sec->floorpic = sides[line->sidenum[0]].sector->floorpic;
        plat->high = P_FindNextHighestFloor(sec,sec->floorheight);
        plat->wait = 0;
        plat->status = up;
        // NO MORE DAMAGE, IF APPLICABLE
        sec->special = 0;

        S_StartSound(&sec->soundorg,sfx_stnmov);
        break;

      case raiseAndChange:
        plat->speed = PLATSPEED/2;
        sec->floorpic = sides[line->sidenum[0]].sector->floorpic;
        plat->high = sec->floorheight + amount*FRACUNIT;
        plat->wait = 0;
        plat->status = up;

        S_StartSound(&sec->soundorg,sfx_stnmov);
        break;

      case downWaitUpStay:
        plat->speed = PLATSPEED * 4;
        plat->low = P_FindLowestFloorSurrounding(sec);

        if (plat->low > sec->floorheight)
        plat->low = sec->floorheight;

        plat->high = sec->floorheight;
        plat->wait = TICRATE*PLATWAIT;
        plat->status = down;
        S_StartSound(&sec->soundorg,sfx_pstart);
        break;

      case blazeDWUS:
        plat->speed = PLATSPEED * 8;
        plat->low = P_FindLowestFloorSurrounding(sec);

        if (plat->low > sec->floorheight)
        plat->low = sec->floorheight;

        plat->high = sec->floorheight;
        plat->wait = TICRATE*PLATWAIT;
        plat->status = down;
        S_StartSound(&sec->soundorg,sfx_pstart);
        break;

      case perpetualRaise:
        plat->speed = PLATSPEED;
        plat->low = P_FindLowestFloorSurrounding(sec);

        if (plat->low > sec->floorheight)
        plat->low = sec->floorheight;

        plat->high = P_FindHighestFloorSurrounding(sec);

        if (plat->high < sec->floorheight)
        plat->high = sec->floorheight;

        plat->wait = TICRATE*PLATWAIT;
        plat->status = P_Random()&1;

        S_StartSound(&sec->soundorg,sfx_pstart);
        break;
    }
    P_AddActivePlat(plat);
    }
    return rtn;
}



void P_ActivateInStasis(int tag)
{
    int     i;

    for (i = 0;i < MAXPLATS;i++)
    if (activeplats[i]
        && (activeplats[i])->tag == tag
        && (activeplats[i])->status == in_stasis)
    {
        (activeplats[i])->status = (activeplats[i])->oldstatus;
        (activeplats[i])->thinker.function.acp1
          = (actionf_p1) T_PlatRaise;
    }
}

void EV_StopPlat(line_t* line)
{
    int     j;

    for (j = 0;j < MAXPLATS;j++)
    if (activeplats[j]
        && ((activeplats[j])->status != in_stasis)
        && ((activeplats[j])->tag == line->tag))
    {
        (activeplats[j])->oldstatus = (activeplats[j])->status;
        (activeplats[j])->status = in_stasis;
        (activeplats[j])->thinker.function.acv = (actionf_v)NULL;
    }
}

void P_AddActivePlat(plat_t* plat)
{
    int     i;

    for (i = 0;i < MAXPLATS;i++)
    if (activeplats[i] == NULL)
    {
        activeplats[i] = plat;
        return;
    }
    I_Error ("P_AddActivePlat: no more plats!");
}

void P_RemoveActivePlat(plat_t* plat)
{
    int     i;
    for (i = 0;i < MAXPLATS;i++)
    if (plat == activeplats[i])
    {
        (activeplats[i])->sector->specialdata = NULL;
        P_RemoveThinker(&(activeplats[i])->thinker);
        activeplats[i] = NULL;

        return;
    }
    I_Error ("P_RemoveActivePlat: can't find plat!");
}
